It has become well known to produce crop harvesting headers which use rotary cutters in replacement of the sickle-knife systems conventionally used in the past. It is well known that such rotary cutters include a cutter bar or gear train which provides the main structural and drive communication components of the cutter. The cutter bar provides a series of longitudinally spaced vertical drive members each of which drives a respective one of a plurality of cutting disks at spaced positions along the cutter bar. The disks are mounted for rotation about respective vertical axes standing upwardly from the cutter bar. The disks, at points on their outer edge, carry a multiple, generally two, flail type blades which rotate with the disk around the vertical axis in a cutting action.
In headers that are configured to not only cut the crop from the field, but also to perform a conditioning function to crimp or break the stalks of the cut crop to achieve faster, more uniform drying of the same in the windrow or swath of material left behind the header, it is common to use a pair of counter-rotating horizontal rollers positioned one above the other behind the rotary cutters. The counter-rotation acts to feed the cut crop material rearward through a nip defined between the two rollers, where close spacing or intermeshing of the rollers at this nip causes the desired conditioning of the material.
Conventionally, the rotational axes of the conditioning rollers are arranged with the axis of the top roller set somewhat forwardly of the axis of the lower roller so that the top roller leads the lower roller by a small amount in the forward working direction in which the header is conveyed over the ground during use. That is, the roller axes are situated in an obliquely sloped plane that is forwardly inclined. This way, the nip between the rollers points obliquely downward in the forward direction and obliquely upward in the rearward direction, so that the crop material is directed somewhat upward from the rollers to discharge cleanly from the rear of the machine to form a swath or windrow behind the header.
Some mower conditioners have added additional features behind the conditioner rolls to further contribute to an upward directional path of the crop material as it moves rearward from the same.
U.S. Pat. No. 7,059,108 (Rosenbalm et al.), issued Jun. 13, 2006 and assigned to Deere & Company, adds a deflector plate behind a forwardly inclined pair of conditioning rollers to intersect a rearward flight path of the crop material from the rollers and steepen the angle of this flight path to increase a force with which the crop material impacts an overhead swath forming shield at the rear of the header.
Towed mower conditioners in the Novacat T series from Pottinger now include models that employ an accelerator roller positioned behind a forwardly inclined pair of conditioning rollers to impart further upward acceleration so as to convey the crop material onto a cross-conveyor for laterally discharging the material from the machine, for example for the purposes of merging the windrow from a side pull mower conditioner unit towed behind a tractor with that of a central mower conditioner header mounted at the front the tractor, whereby material from both units can be efficiently collected in a single pass of the field.
Suitable placement of the set of conditioning rolls behind a rotary cutterbar is difficult, because the hay must be fed into the nip, and contact of the hay with the rollers above and below the top and bottom roller axes can result in the crop being rejected forwardly back into the cutting zone, which can cause poor material flow and poor cut quality. The aforementioned conventional positioning of the top conditioning roll forward of rear roll can significantly contribute to the rejection of crop material back into the cutting zone, as contact of the cut crop material with the top roller above its rotational axis kicks the material forwardly downward, i.e. back toward the disks of the cutterbar.
Applicant has developed a unique mower conditioner configuration that reduces rejection of the cut crop material from the conditioning rollers back into the cutting zone and improves the flow of material through the machine.